Video redirection across multiple information handling systems (IHSs) using a graphics core and a bus bridge integrated into an enclosure controller (EC)

ABSTRACT

Embodiments of systems and methods for providing video redirection across multiple Information Handling Systems (IHSs) are discussed. In some embodiments, a method may include: receiving, via a video redirection client, a video stream produced by a video redirection server executed by a Baseboard Management Controller (BMC) of a selected IHS; providing the video stream to a framebuffer driver, where the frame buffer driver is configured to: (i) store frame data from the video stream onto a framebuffer memory; and (ii) in response to a determination that a host is not available, transmit control signals to a graphics core via an Advanced Microcontroller Bus Architecture (AMBA) high-performance bus (AHB)-to-Peripheral Component Interconnect (PCI) (AHB-to-PCI) bridge, where the graphics core is accessible via a PCI bus exclusively when the host is available; and transmitting the frame data to a display coupled to the chassis.

FIELD

The present disclosure generally relates to Information Handling Systems (IHSs), and, more particularly, to systems and methods for providing video redirection across multiple IHSs using a graphics core and a bus bridge integrated into an Enclosure Controller (EC).

BACKGROUND

As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is Information Handling Systems (IHSs). An IHS generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, IHSs may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in IHSs allow for IHSs to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, IHSs may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.

IHSs are often installed within a chassis or rack. In some cases, it is possible to use the same keyboard, video, and mouse (KVM) to interact with any given one of several IHSs in a chassis, one at a time, under control of an Enclosure Controller (EC) or Chassis Management Controller (CMC).

SUMMARY

Embodiments of systems and methods for video redirection across multiple Information Handling Systems (IHSs) using a graphics core and a bus bridge integrated into an Enclosure Controller (EC) are described. In an illustrative, non-limiting embodiment, an EC is coupled to a plurality of IHSs in a chassis, the EC comprising: a processor core; a graphics core coupled to the processor core via an Advanced Microcontroller Bus Architecture (AMBA) high-performance bus (AHB)-to-Peripheral Component Interconnect (PCI) (AHB-to-PCI) bridge, where the graphics core is accessible to the processor core via a PCI bus through a host; a memory coupled to the processor core, the memory having program instructions stored thereon that, upon execution, cause the EC to: receive, via a video redirection client, a video stream produced by a video redirection server executed by a Baseboard Management Controller (BMC) of a selected IHS coupled to the chassis; provide the video stream to a framebuffer driver, where the frame buffer driver is configured to: (i) store frame data from the video stream onto a framebuffer memory; and (ii) in response to a determination that the host is not available, transmit control signals to the graphics core via the AHB-to-PCI bridge; and transmit the frame data to a display coupled to the chassis.

For example, the video redirection client may include at least one of: a Virtual Network Computing (VNC) client, a Secure Shell (SSH) client, a web browser, or a serial terminal. Moreover, the video redirection server may include at least one of: a Virtual Network Computing (VNC) server or an Original Equipment Manufacturer (OEM) server.

To provide the video stream to the framebuffer driver, the program instructions, upon execution, may cause the EC to maintain a Qt interface between the video redirection client and the framebuffer driver. The program instructions, upon execution, may cause the EC to receive a keyboard or mouse event at the Qt interface, and transmit the keyboard or mouse event to the selected IHS. The program instructions, upon execution, may cause the EC to enable a user to select the IHS among the plurality of IHSs using the Qt interface to establish a remote desktop session.

In some cases, the framebuffer driver further may include a Linux framebuffer (fbdev) configured to access the framebuffer memory under a Linux kernel. To transmit the control signals via the AHB-to-PCI bridge, the framebuffer driver may be configured to use an input-output control (IOCTL) interface. The control signals may indicate at least one of: a pixel resolution, color depth, or a refresh rate. The graphics core may be configured to retrieve the frame data from the framebuffer memory in response to a command received via the AHB-to-PCI bridge.

In another illustrative, non-limiting embodiment, a hardware memory of an EC configured to manage a plurality of IHSs coupled to a chassis, the hardware memory having program instructions stored thereon that, upon execution, cause the EC to: receive, via a video redirection client, a video stream produced by a video redirection server executed by a BMC of a selected IHS; provide the video stream to a framebuffer driver, where the frame buffer driver is configured to: (i) store frame data from the video stream onto a framebuffer memory; and (ii) in response to a determination that a host is not available, transmit control signals to a graphics core within the EC via an AHB-to-PCI bridge, where the graphics core is accessible to a processing core of the EC via a PCI bus through the host only when the host is available; and transmit the frame data to a display coupled to the chassis.

The video redirection client may include a VNC client and the video redirection server comprises a VNC server. To provide the video stream to the framebuffer driver, the program instructions, upon execution, may cause the EC to maintain a Qt interface between the video redirection client and the framebuffer driver. The program instructions, upon execution, further cause the EC to receive a keyboard or mouse event at the Qt interface, and transmit the keyboard or mouse event to the selected IHS. The program instructions, upon execution, may cause the EC to enable a user to select the IHS among the plurality of IHSs using the Qt interface to establish a remote desktop session.

The framebuffer driver further may include a Linux framebuffer configured to access the framebuffer memory. The control signals further indicate at least one of: a pixel resolution, color depth, or a refresh rate. The graphics core may be configured to retrieve the frame data from the framebuffer memory in response to a command received via the AHB-to-PCI bridge.

In yet another illustrative, non-limiting embodiment, a method may include receiving, via a video redirection client, a video stream produced by a video redirection server executed by a BMC of a selected IHS; providing the video stream to a framebuffer driver, where the frame buffer driver is configured to: (i) store frame data from the video stream onto a framebuffer memory; and (ii) in response to a determination that a host is not available, transmit control signals to a graphics core via an AHB-to-PCI bridge, where the graphics core is accessible via a PCI bus exclusively when the host is available; and transmitting the frame data to a display coupled to the chassis.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention(s) is/are illustrated by way of example and is/are not limited by the accompanying figures. Elements in the figures are illustrated for simplicity and clarity, and have not necessarily been drawn to scale.

FIG. 1 is a diagram illustrating components of an Enclosure Controller (EC) configured to perform video redirection using an integrated graphics core and bus bridge, according to some embodiments.

FIG. 2 is a diagram illustrating components of an Information Handling System (IHS), according to some embodiments.

FIG. 3 is a diagram illustrating components of a chassis or rack, according to some embodiments.

DETAILED DESCRIPTION

For purposes of this disclosure, an IHS may include any instrumentality or aggregate of instrumentalities operable to compute, calculate, determine, classify, process, transmit, receive, retrieve, originate, switch, store, display, communicate, manifest, detect, record, reproduce, handle, or utilize any form of information, intelligence, or data for business, scientific, control, or other purposes. For example, an IHS may be a personal computer (e.g., desktop or laptop), tablet computer, mobile device (e.g., Personal Digital Assistant (PDA) or smart phone), server (e.g., blade server or rack server), a network storage device, or any other suitable device and may vary in size, shape, performance, functionality, and price. An IHS may include Random Access Memory (RAM), one or more processing resources such as a Central Processing Unit (CPU) or hardware or software control logic, Read-Only Memory (ROM), and/or other types of nonvolatile memory. Additional components of an IHS may include one or more disk drives, one or more network ports for communicating with external devices as well as various I/O devices, such as a keyboard, a mouse, touchscreen, and/or a video display. As described, an IHS may also include one or more buses operable to transmit communications between the various hardware components. An example of an IHS is described in more detail below.

In various embodiments, systems and methods described herein enable video redirection across multiple IHSs using a graphics core and a bus bridge integrated into an Enclosure Controller (EC) or Chassis Management Controller (CMC) of a chassis or rack. Particularly, an EC or CMC may be configured to: (i) receive keyboard and mouse inputs from a user operating the chassis during a video redirection session (e.g., desktop sharing or the like) and transmit those inputs to a target IHS in the chassis; and (ii) receive and graphics produced by the target IHS during the video redirection session for local display.

With respect to video redirection technologies, virtual Keyboard, Video, and Mouse (vKVM) is a software application that enables video, keyboard, and mouse redirection in Baseboard Management Controllers (BMCs) and other service processors. To use vKVM, a client IHS installs browser plugins (e.g., “Active X” or “Java”) or uses Hypertext Markup Language (HTML) web sockets, to access the video output of a target IHS over a network. Protocols that support vKVM include, but are not limited to, Dambrackas Video Compression (DVC), American Megatrend's (AMI's) Advanced Adaptive Video Compression Algorithm (AAVICA), etc.

Another example of a video redirection technology in use today is Virtual Network Computing (VNC), which uses the Remote Frame Buffer protocol (RFB). A VNC client transmits keyboard and mouse events from the client IHS to the target IHS, relaying graphical screen updates back in the other direction, over a network. Yet other video redirection technologies include the Remote Desktop Protocol (RDP) and other proprietary and Original Equipment Manufacturer (OEM) protocols (e.g., such as Integrated Lights-Out or “iLO”, etc.).

Various embodiments described herein may be implemented in an EC or CMC. In some implementations, an EC may include a processor core, a graphics core, and a memory. The graphics core may be coupled to the processor core via an Advanced Microcontroller Bus Architecture (AMBA) high-performance bus (AHB)-to-Peripheral Component Interconnect (PCI) (AHB-to-PCI) bridge. For example, the processor core may be an ARM core and the graphics core may be a Matrox Graphics Inc. (MGA) core.

When the EC is implemented as an IHS (coupled to the chassis), the graphics core is coupled to a host Central Processing Unit (CPU)'s PCI bus as a normal video device; but the processor core integrated into the EC lacks a PCI connection to the graphics core. Accordingly, the PCI bus of the host CPU is employed to provide video redirection during a KVM session. In this scenario, the AHB-PCI bridge is used by the processor core only for sending PCI configuration access cycles to the graphics core.

From an EC's Operating System (OS) environment (e.g., Linux), however, it may sometimes be necessary for the processing core to initialize the graphics core and the drive video output without access to the graphics core over PCI due to an unavailable host CPU. To this end, the graphics core may use the EC's memory (e.g., RAM) as its video framebuffer so that the processing core can “scrape” the framebuffer outside the context of a host—that is, when the CPU (separate from the EC's processing core) is not available (e.g., powered down or off, etc.).

In some embodiments, in the kernel space, a graphics driver that would otherwise rely upon PCI access to configure the graphics core may be modified to use the AHB-to-PCI bus bridge instead. For instance, references in a Linux driver (fbdev) that access the graphics core over PCI may be substituted by a shim function that accesses the graphics core using the AHB-to-PCI bridge. In the same implementation, a shared RAM framebuffer may be mapped into Linux using the modified fbdev driver.

In various implementations, a modified fbdev driver may include a set of Application Programming Interface (APIs), commands, or functions to read and to write Graphics control registers, and to perform AHBPCI configuration over the AHB-PCI Bus. Additionally, or alternatively, a modified fbdev driver may initialize and configure the graphics core for through AHB-PCI bridge interface instead of the PCI bus, and it may initialize and configure a framebuffer pointer with the graphics core's memory address. Additionally, or alternatively, a modified fbdev driver may setup and/or update to pixel PLL set up, resolution set up, vertical and horizontal sync, and refresh rate. Additionally, or alternatively, a modified fbdev driver may be configured to perform a change in resolution or timing parameters passed through the AHB-PCI bus APIs.

In the user space, a Qt (cute) graphical windowing environment may enable on-screen display (OSD) and/or VNC client to render a video output and to provide the video to the fbdev device. The fbdev device has the framebuffer memory mapped, hence video output rendered to fbdev device is loaded onto the framebuffer. Any resolution change initiated by the user or VNC client may be sent using an input/output control (IOCTL) interface. As such, systems and methods described herein provide a standard access to framebuffer which can be utilized by any user application, without requiring modifications to every user application (to extract video frames and write them onto a framebuffer memory).

As used herein, the term “framebuffer” refers to a portion of memory containing a bitmap that drives a video display—that is, is a memory buffer containing at least one complete frame of data. The information in a framebuffer may include color values for every pixel to be shown on a display. Color values are commonly stored in any suitable number of bits. In some cases, an alpha channel may provide additional information about pixel transparency. The amount of memory required for a framebuffer depends upon the resolution of the video frames as well as on color depth and/or palette. In many implementations, a software framebuffer, such as fbdev in Linux, may emulate the operation of a hardware framebuffer by abstracting the physical method for accessing the underlying device into a memory map.

FIG. 1 is a diagram illustrating an example of an Enclosure Controller (EC) 101 in chassis 100 having a plurality of IHSs 102A-N (e.g., blades or sleds) coupled thereto. In operation, Universal Serial Bus (USB) Human Interface Device (HID) device module 123 and USB host device 124 capture keyboard 121 and/or mouse 122 events, and relay those events to a selected IHS 102. The user visually interacts with the selected IHS 102 using a local display configured to render video signal 120. Specifically, EC 101 provides video redirection for video content produced by video hardware 104 in selected IHS 102 to video port 119 (e.g., VGA, DisplayPort, HDMI, etc.).

As shown in FIG. 1, each of the plurality of IHSs 102A-N includes its own BMC 103. Each BMC 103 in turn includes video hardware (e.g., an integrated video core) and executes VNC server 105 and/or OEM server 106, each configured to output a video signal during a video redirection session using a respective protocol (e.g., RFB, proprietary, etc.).

EC 101 executes one or more of: on-screen display (OSD) module 109, VNC client 110, Secure Shell (SSH) client 111, web browser 112, and/or serial terminal 113. One or more of these components may be configured to receive a video signal from a corresponding server in BMC 103. For example, VNC client 110 in EC 101 may establish a connection with VNC server 105 of BMC 103 to effect a video redirection operation with IHS 102.

EC 101 may include user space 107 and kernel space 108. As used herein, kernel space 108 comprises memory reserved for running an OS kernel, kernel extensions, and most device drivers. In contrast, user space 107 comprises the remainder of the memory where application software and some drivers execute.

User space 107 also includes Qt framework 114. In various embodiments, Qt framework 114 may include a Graphical User Interface (GUI) widget toolkit, or a command-line tool or console configured to provide any of modules 109-113 with access to framebuffer driver 115 in kernel space 108. Qt framework 114 may also provide any of modules 109-113 with uniform access to keyboard and mouse events originated by USB host 124.

Framebuffer driver 115 receives the output from VNC client 110, for example, and configures graphics processor 118 for a KVM session using AHB-PCI bridge 117 instead of a normal PCI bus (through a host CPU coupled to EC 101; not shown). Meanwhile, framebuffer driver 115 stores video frames received from VNC client 110 onto framebuffer memory 116.

To output video 120, framebuffer driver 115 commands graphics core 118 to scrape framebuffer memory 116 directly and without having to rely on the operation of the host CPU's PCI bus. In some cases, use of framebuffer driver 115 in this manner may be triggered in response to a determination that the host is not available, such as when the host CPU is powered down, powered off, or overloaded.

At the outset of a video redirection session, FB driver 115 may use AHB-to-PCI bridge 117 to initialize graphics core 118. In some cases, VNC client 110 may display a menu of IHSs 102A-N installed in chassis 100 via Qt framework 114, and a user may select one of IHSs 102A-N manually. VNC client 110 then requests video redirection, desktop sharing, and/or KVM access and control from VNC server 105 of selected IHS 102. As such, EC 101 retrieves graphics, video, or image frames produced by video hardware 104 of BMC 103.

In some cases, FB driver 115 determines the selected IHS 102's current resolution and changes the local resolution to match the selected IHS 102's current resolution. FB driver 115 extracts the video and updates framebuffer memory 116. Graphics core 118 converts the contents of framebuffer memory 116 to video output 120 (e.g., an analog video output interface such as a VGA, or a digital video output interface such as a high-definition multimedia interface (HDMI) or DisplayPort).

In some cases, various parameters for the video redirection session may be handled via AHB-PCI bridge 117 including, but not limited to: (i) a minimum, maximum and/or range of bandwidth(s) for the video output (e.g., Kb/s); (ii) a minimum, maximum, or range of pixel resolution(s) (e.g., VGA or SVGA); (iii) a minimum, maximum, or range of frame rates (e.g., 20-30 fps); and/or (iv) software license verification information (e.g., user credentials, etc.).

In some cases, FB Driver 115 may dynamically determine whether to use AHB-PCI bridge 117 or the host CPU's PCI channel, when the host is available, based upon platform specific data passed through device tree identifying the bus type, in addition to the base address of the bus. The bus type will be AHB-PCI for certain types of processors (e.g., Nuvoton) and it will be PCI bus in all other platforms where a host CPU is available.

FIG. 2 shows an example of an IHS 102 configured to implement systems and methods described herein. In some implementations, IHS 102 may be a computing component, such as a sled or blade, configured to share infrastructure resources provided by a chassis, for example, as shown in FIG. 9 (e.g., 905 a-n and/or 915 a-n). It should be appreciated, however, that although these embodiments show an IHS as sled or blade, other IHS implementations may be utilized including, but not limited to: desktops, laptops, appliances, and mobile devices, etc.

In some embodiments, processor(s) 205 may include a main processor and a co-processor, each of which may include a plurality of processing cores that, in certain scenarios, may each be used to run an instance of a server. In certain embodiments, one or all of processor(s) 205 may be graphics processing units (GPUs) in scenarios where IHS 102 has been configured to support functions such as multimedia services and graphics applications.

As illustrated, processor(s) 205 includes integrated memory controller 205 a that may be implemented directly within the circuitry of processor 205, or memory controller 205 a may be a separate integrated circuit that is located on the same die as processor 205. Memory controller 205 a may be configured to manage the transfer of data to and from system memory 210 of IHS 102 via high-speed memory interface 205 b.

System memory 210 is coupled to processor(s) 205 via memory bus 205 b that provides processor(s) 205 with high-speed memory used in the execution of computer program instructions. Accordingly, system memory 210 may include memory components, such as such as static RAM (SRAM), dynamic RAM (DRAM), NAND Flash memory, suitable for supporting high-speed memory operations by the processor(s) 205. In certain embodiments, system memory 210 may combine both persistent, non-volatile memory and volatile memory.

In certain embodiments, system memory 210 may be include multiple removable memory modules. System memory 210 includes removable memory modules 210 a-n. Each of removable memory modules 210 a-n may correspond to a printed circuit board memory socket that receives corresponding module 210 a-n, such as a DIMM (Dual In-line Memory Module), that can be coupled to the socket and then decoupled from the socket as needed, such as to upgrade memory capabilities or to replace faulty components. In other embodiments of IHS, system memory 210 may be configured with memory socket interfaces that correspond to different types of removable memory module form factors, such as a Dual In-line Package (DIP) memory, a Single In-line Pin Package (SIPP) memory, a Single In-line Memory Module (SIMM), and/or a Ball Grid Array (BGA) memory.

IHS 102 may utilize a chipset implemented by integrated circuits that are connected to each processor 205. All or portions of the chipset may be implemented directly within the integrated circuitry of an individual processor 205. The chipset may provide the processor(s) 205 with access to a variety of resources accessible via one or more buses 215. Various embodiments may utilize any number of buses to provide the illustrated pathways served by bus 215. In certain embodiments, bus 215 may include a PCIe (PCI Express) switch fabric that is accessed via a PCIe root complex. IHS 102 may also include one or more I/O ports 250, such as PCIe ports, that may be used to couple the IHS 102 directly to other IHSs, storage resources or other peripheral components.

As illustrated, a variety of resources may be coupled to processor(s) 205 of IHS 102 via bus 215. For instance, processor(s) 205 may be coupled to network controller 225, such as provided by a Network Interface Controller (NIC) that is coupled to IHS 102 and allows IHS 102 to communicate via an external network, such as the Internet or a LAN. Processor(s) 205 may also be coupled to power management unit 260 that may interface with (the power system unit of a chassis) in which IHS 102 may be installed as a sled or blade. In certain embodiments, graphics processor 235 may be included within one or more video or graphics cards, or an embedded controller, installed as components of IHS 102. In certain embodiments, graphics processor 235 may be an integrated part of BMC 103 and may be utilized to support the display of diagnostic and administrative interfaces related to IHS 102 via display devices that are coupled, either directly or remotely, to BMC 103.

As illustrated, IHS 102 may include one or more FPGA (Field-Programmable Gate Array) card(s) 220. Each of FPGA card(s) 220 supported by IHS 102 may include various processing and memory resources, in addition to an FPGA integrated circuit that may be reconfigured after deployment of IHS 102 through programming functions supported by the FPGA card 220. Each individual FGPA card 220 may be optimized to perform specific processing tasks, such as specific signal processing, security, data mining, and artificial intelligence functions, and/or to support specific hardware coupled to IHS 102.

In certain embodiments, IHS 102 may operate using a Basic Input/Output System (BIOS) that may be stored in a non-volatile memory accessible by processor(s) 205. The BIOS may provide an abstraction layer by which the operating system (OS) of the IHS 102 interfaces with its hardware components. Upon powering or restarting IHS 102, processor(s) 205 may utilize BIOS instructions to initialize and test hardware components, including both components permanently installed as components of the motherboard of IHS 102 and removable components installed within various expansion slots supported by the IHS 102. The BIOS instructions may also load an OS. In certain embodiments, IHS 102 may utilize Unified Extensible Firmware Interface (UEFI) in addition to or instead of a BIOS. In certain embodiments, the functions provided by a BIOS may be implemented, in full or in part, by BMC 103.

In certain embodiments, BMC 103 may operate from a different power plane from processor(s) 205 and other components of IHS 103, thus allowing BMC 103 to operate, and management tasks to proceed, while the processing cores of IHS 103 are powered off. As described, various functions provided by the BIOS, including launching the OS of IHS 103, may be implemented by BMC 103. In some embodiments, BMC 103 may perform various functions to verify the integrity of IHS 103 and its hardware components prior to initialization (e.g., in a bare-metal state).

BMC 103 may include service processor 255 a, or specialized microcontroller, that operates management software that supports remote monitoring and administration of IHS 102. BMC 103 may be installed on the motherboard of IHS 102 or may be coupled to IHS 102 via an expansion slot provided by the motherboard. In support of remote monitoring functions, network adapter 255 c may support connections with BMC 103 using wired and/or wireless network connections via a variety of network technologies.

As a non-limiting example of a BMC, the integrated Dell BMC (iDRAC) from Dell® is embedded within Dell PowerEdge™ servers and provides functionality that helps information technology (IT) administrators deploy, update, monitor, and maintain servers remotely.

In some embodiments, BMC 103 may support monitoring and administration of various managed devices 220, 225, 230, 280 of an IHS via a sideband bus interface. For instance, messages utilized in device management may be transmitted using I2C sideband bus connections 275 a-d that may be individually established with each of the respective managed devices 220, 225, 230, 280 through the operation of I2C multiplexer 255 d of BMC 103. As illustrated, certain of the managed devices of IHS 102, such as FPGA cards 220, network controller 225 and storage controller 230, are coupled to the IHS processor(s) 205 via in-line bus 215, such as a PCIe root complex, that is separate from the I2C sideband bus connections 275 a-d used for device management. The management functions of BMC 103 may utilize information collected by various managed sensors 280 located within the IHS. For instance, temperature data collected by sensors 280 may be utilized by BMC 103 in support of closed-loop airflow cooling of the IHS 102.

In certain embodiments, the service processor 255 a of BMC 103 may rely on an I2C co-processor 255 b to implement sideband I2C communications between BMC 103 and managed components 220, 225, 230, 280 of the IHS. The I2C co-processor 255 b may be a specialized co-processor or micro-controller that is configured to interface via a sideband I2C bus interface with the managed hardware components 220, 225, 230, 280 of IHS. In some embodiments, I2C co-processor 255 b may be an integrated component of service processor 255 a, such as a peripheral system-on-chip feature that may be provided by service processor 255 a.

Each I2C bus 275 a-d is illustrated as a single line in FIG. 2. However, in various implementations, each I2C bus 275 a-d may include of a clock line and data line that couple BMC 103 to I2C endpoints 220 a, 225 a, 230 a, 280 a which may be identified as modular field replaceable units (FRUs).

In various scenarios, a portion of managed devices 220, 225, 230, 280 may support I2C bus 275 a-d communications that utilize IPMI (Management Component Transport Protocol) messaging. For instance, certain types of legacy and less-sophisticated managed devices, such as temperature sensors 280, may utilize IPMI messaging and may thus be identified on the I2C bus 275 d as an IPMI endpoints by the I2C coprocessor 255 b. IHS 102 may include a variety of IPMI sensors 280 that collect various types of readings, such as intrusion detection and power consumption.

In providing sideband management capabilities, I2C co-processor 255 b may each interoperate with corresponding endpoint I2C controllers 220 a, 225 a, 230 a, 280 a that implement the I2C communications of respective managed devices 220, 225, 230. Endpoint I2C controllers 220 a, 225 a, 230 a, 280 a may be implemented as a dedicated microcontroller for communicating sideband I2C messages with BMC 103, or endpoint I2C controllers 220 a, 225 a, 230 a, 280 a may be integrated SoC functions of a processor of the respective managed device endpoints 220, 225, 230, 280.

In various embodiments, IHS 102 does not include each of the components shown in FIG. 2. In various embodiments, IHS 102 may include various additional components in addition to those that are shown in FIG. 2. Furthermore, some components that are represented as separate components in FIG. 2 may in certain embodiments instead be integrated with other components. For example, in certain embodiments, all or a portion of the functionality provided by the illustrated components may instead be provided by components integrated into one or more processor(s) 205 as a systems-on-a-chip (SoC).

IHS 102 of FIG. 2 may be a compute sled, such as compute sleds 305 a-n of FIG. 3 below, that may be installed within a chassis, that may in turn be installed within a rack. Installed in this manner, IHS 102 may utilized shared power, network and cooling resources provided by the chassis and/or rack.

FIG. 3 is a diagram illustrating components of a chassis or rack 100 comprising one or more compute sleds 305 a-n and one or more storage sleds 315 a-n that may be configured to implement the systems and methods described herein. Chassis 100 may include one or more bays that each receive an individual sled (that may be additionally or alternatively referred to as a tray, blade, and/or node), such as compute sleds 305 a-n and storage sleds 315 a-n. Chassis 100 may support a variety of different numbers (e.g., 4, 8, 16, 32), sizes (e.g., single-width, double-width) and physical configurations of bays.

Other embodiments may include additional types of sleds that provide various types of storage and/or processing capabilities. Other types of sleds may provide power management and networking. Sleds may be individually installed and removed from the chassis 100, thus allowing the computing and storage capabilities of a chassis to be reconfigured by swapping the sleds with different types of sleds, in many cases without affecting the operations of the other sleds installed in chassis 100.

Multiple chassis 100 may be housed within a rack. Data centers may utilize large numbers of racks, with various different types of chassis installed in the various configurations of racks. The modular architecture provided by the sleds, chassis and rack allow for certain resources, such as cooling, power and network bandwidth, to be shared by compute sleds 305 a-n and storage sleds 315 a-n, thus providing efficiency improvements and supporting greater computational loads.

Chassis 100 may be installed within a rack structure that provides all or part of the cooling utilized by chassis 100. For airflow cooling, a rack may include one or more banks of cooling fans that may be operated to ventilate heated air from within the chassis 100 that is housed within the rack. Chassis 100 may alternatively or additionally include one or more cooling fans 330 that may be similarly operated to ventilate heated air from within the sleds 305 a-n, 315 a-n installed within the chassis. A rack and chassis 100 installed within the rack may utilize various configurations and combinations of cooling fans to cool the sleds 305 a-n, 315 a-n and other components housed within chassis 100.

Sleds 305 a-n, 315 a-n may be individually coupled to chassis 100 via connectors that correspond to the bays provided by chassis 100 and that physically and electrically couple an individual sled to backplane 360.

Chassis backplane 360 may be a printed circuit board that includes electrical traces and connectors that are configured to route signals between the various components of chassis 100 that are connected to backplane 360. In various embodiments, backplane 360 may include various additional components, such as cables, wires, midplanes, backplanes, connectors, expansion slots, and multiplexers. In certain embodiments, backplane 360 may be a motherboard that includes various electronic components installed thereon. Such components installed on motherboard backplane 360 may include components that implement all or part of the functions described with regard to SAS (Serial Attached SCSI) expander 350, I/O controllers 345, network controller 340, and power supply unit 335.

In certain embodiments, compute sleds 305 a-n may be IHSs such as described with regard to IHS 102 of FIG. 2. Compute sleds 305 a-n may provide computational processing resources that may be used to support a variety of e-commerce, multimedia, business and scientific computing applications, such as services provided via a cloud implementation. Compute sleds 305 a-n are typically configured with hardware and software that provide leading-edge computational capabilities. Accordingly, services provided using such computing capabilities are typically provided as high-availability systems that operate with minimum downtime. As described in additional detail with regard to FIG. 2, compute sleds 305 a-n may be configured for general-purpose computing or may be optimized for specific computing tasks.

As illustrated, each compute sled 305 a-n includes a respective BMC 310 a-n. As described in additional detail with regard to FIG. 2, each BMC 310 a-n provides capabilities for remote monitoring and management of its respective compute sled 305 a-n. In support of these monitoring and management functions, BMCs 310 a-n may utilize both in-band and sideband (i.e., out-of-band) communications with various components of a compute sled 305 a-n and chassis 100. BMC 310 a-n may collect sensor data, such as temperature sensor readings, from components of the chassis 100 in support of airflow cooling of the chassis 100 and the sleds 305 a-n, 315 a-n. In addition, each BMC 310 a-n may implement various monitoring and administrative functions related to compute sleds 305 a-n that require sideband bus connections with various internal components of the respective compute sleds 305 a-n.

As described in above, BMCs 310 a-n may provide capabilities support remote monitoring and managing of IHSs, such as compute sleds 305 a-n.

As illustrated, chassis 100 also includes one or more storage sleds 315 a-n that are coupled to backplane 360 and installed within one or more bays of chassis 100 in a similar manner to compute sleds 305 a-n. Each of individual storage sleds 315 a-n may include various different numbers and types of storage devices. For instance, storage sleds 315 a-n may include SAS (Serial Attached SCSI) magnetic disk drives, SATA (Serial Advanced Technology Attachment) magnetic disk drives, solid-state drives (SSDs) and other types of storage drives in various combinations. Storage sleds 315 a-n may be utilized in various storage configurations by compute sleds 305 a-n that are coupled to chassis 100.

Each of compute sleds 305 a-n includes storage controller 335 a-n that may be utilized to access storage drives that are accessible via chassis 100. Some of the individual storage controllers 335 a-n may provide support for RAID (Redundant Array of Independent Disks) configurations of logical and physical storage drives, such as storage drives provided by storage sleds 315 a-n. In some embodiments, some or all of individual storage controllers 335 a-n may be HBAs (Host Bus Adapters) that provide more limited capabilities in accessing physical storage drives provided via storage sleds 315 a-n and/or via SAS expander 350.

In addition to the data storage capabilities provided by storage sleds 315 a-n, chassis 100 may provide access to other storage resources that may be installed components of chassis 100 and/or may be installed elsewhere within a rack housing the chassis 100, such as within a storage blade. In certain scenarios, such storage resources 355 may be accessed via a SAS expander 350 that is coupled to backplane 360 of the chassis 100.

SAS expander 350 may support connections to a number of JBOD (Just a Bunch Of Disks) storage drives 355 that may be configured and managed individually and without implementing data redundancy across the various drives 355. Additional storage resources 355 may also be at various other locations within a datacenter in which chassis 100 is installed. Such additional storage resources 355 may also may be remotely located.

As illustrated, chassis 100 of FIG. 3 includes network controller 340 that provides network access to the sleds 305 a-n, 315 a-n installed within the chassis. Network controller 340 may include various switches, adapters, controllers and couplings used to connect chassis 100 to a network, either directly or via additional networking components and connections provided via a rack in which chassis 100 is installed.

Chassis 100 may similarly include power supply unit 335 that provides the components of the chassis with various levels of DC power from an AC power source or from power delivered via a power system provided by a rack within which chassis 100 may be installed. In certain embodiments, power supply unit 335 may be implemented within a sled that may provide chassis 100 with redundant, hot-swappable power supply units.

Chassis 100 may also include various I/O controllers 340 that may support various I/O ports, such as USB ports that may be used to support keyboard and mouse inputs and/or video display capabilities. Such I/O controllers 345 may be utilized by EC 101 to support various KVM (Keyboard, Video and Mouse) 325 a capabilities that provide administrators with the ability to interface with chassis 100 and or its individual blades. EC 101 may also include storage module 325 c that provides capabilities for managing and configuring certain aspects of the storage devices of chassis 100, such as the storage devices provided within storage sleds 315 a-n and within JBOD 355.

In addition to providing support for KVM 325 a capabilities for administering chassis 100, EC 101 may support various additional functions for sharing the infrastructure resources of chassis 100. In some scenarios, EC 101 may implement tools for managing power 335, network bandwidth 340 and airflow cooling 330 that are available via the chassis 100. As described, airflow cooling 330 utilized by chassis 100 may include an airflow cooling system that is provided by a rack in which chassis 100 may be installed and managed by cooling module 325 b of EC 101.

It should be understood that various operations described herein may be implemented in software executed by logic or processing circuitry, hardware, or a combination thereof. The order in which each operation of a given method is performed may be changed, and various operations may be added, reordered, combined, omitted, modified, etc. It is intended that the invention(s) described herein embrace all such modifications and changes and, accordingly, the above description should be regarded in an illustrative rather than a restrictive sense.

Although the invention(s) is/are described herein with reference to specific embodiments, various modifications and changes can be made without departing from the scope of the present invention(s), as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of the present invention(s). Any benefits, advantages, or solutions to problems that are described herein with regard to specific embodiments are not intended to be construed as a critical, required, or essential feature or element of any or all the claims.

Unless stated otherwise, terms such as “first” and “second” are used to arbitrarily distinguish between the elements such terms describe. Thus, these terms are not necessarily intended to indicate temporal or other prioritization of such elements. The terms “coupled” or “operably coupled” are defined as connected, although not necessarily directly, and not necessarily mechanically. The terms “a” and “an” are defined as one or more unless stated otherwise. The terms “comprise” (and any form of comprise, such as “comprises” and “comprising”), “have” (and any form of have, such as “has” and “having”), “include” (and any form of include, such as “includes” and “including”) and “contain” (and any form of contain, such as “contains” and “containing”) are open-ended linking verbs. As a result, a system, device, or apparatus that “comprises,” “has,” “includes” or “contains” one or more elements possesses those one or more elements but is not limited to possessing only those one or more elements. Similarly, a method or process that “comprises,” “has,” “includes” or “contains” one or more operations possesses those one or more operations but is not limited to possessing only those one or more operations. 

The invention claimed is:
 1. An Enclosure Controller (EC) coupled to a plurality of Information Handling Systems (IHSs) in a chassis, the EC comprising: a processor core; a graphics core coupled to the processor core via an Advanced Microcontroller Bus Architecture (AMBA) high-performance bus (AHB)-to-Peripheral Component Interconnect (PCI) (AHB-to-PCI) bridge, wherein the graphics core is accessible to the processor core via a PCI bus through a host; and a memory coupled to the processor core, the memory having program instructions stored thereon that, upon execution, cause the EC to: receive, via a video redirection client, a video stream produced by a video redirection server executed by a Baseboard Management Controller (BMC) of a selected IHS coupled to the chassis; provide the video stream to a framebuffer driver, wherein the frame buffer driver is configured to: (i) store frame data from the video stream onto a framebuffer memory; and (ii) in response to a determination that the host is not available, transmit control signals to the graphics core via the AHB-to-PCI bridge; and transmit the frame data to a display coupled to the chassis.
 2. The EC of claim 1, wherein the video redirection client comprises at least one of: a Virtual Network Computing (VNC) client, a Secure Shell (SSH) client, a web browser, or a serial terminal.
 3. The EC of claim 1, wherein the video redirection server comprises at least one of: a Virtual Network Computing (VNC) server or an Original Equipment Manufacturer (OEM) server.
 4. The EC of claim 1, wherein to provide the video stream to the framebuffer driver, the program instructions, upon execution, further cause the EC to maintain a Qt interface between the video redirection client and the framebuffer driver.
 5. The EC of claim 4, wherein the program instructions, upon execution, further cause the EC to receive a keyboard or mouse event at the Qt interface, and transmit the keyboard or mouse event to the selected IHS.
 6. The EC of claim 4, wherein the program instructions, upon execution, further cause the EC to enable a user to select the IHS among the plurality of IHSs using the Qt interface to establish a remote desktop session.
 7. The EC of claim 1, wherein the framebuffer driver further comprises a Linux framebuffer (fbdev) configured to access the framebuffer memory under a Linux kernel.
 8. The EC of claim 1, wherein to transmit the control signals via the AHB-to-PCI bridge, the framebuffer driver is configured to use an input-output control (IOCTL) interface.
 9. The EC of claim 8, wherein the control signals further indicate at least one of: a pixel resolution, color depth, or a refresh rate.
 10. The EC of claim 8, wherein the graphics core is configured to retrieve the frame data from the framebuffer memory in response to a command received via the AHB-to-PCI bridge.
 11. A hardware memory of an Enclosure Controller (EC) configured to manage a plurality of Information Handling Systems (IHSs) coupled to a chassis, the hardware memory having program instructions stored thereon that, upon execution, cause the EC to: receive, via a video redirection client, a video stream produced by a video redirection server executed by a Baseboard Management Controller (BMC) of a selected IHS; provide the video stream to a framebuffer driver, wherein the frame buffer driver is configured to: (i) store frame data from the video stream onto a framebuffer memory; and (ii) in response to a determination that a host is not available, transmit control signals to a graphics core within the EC via an Advanced Microcontroller Bus Architecture (AMBA) high-performance bus (AHB)-to-Peripheral Component Interconnect (PCI) (AHB-to-PCI) bridge, wherein the graphics core is accessible to a processing core of the EC via a PCI bus through the host only when the host is available; and transmit the frame data to a display coupled to the chassis.
 12. The hardware memory of claim 11, wherein the video redirection client comprises a Virtual Network Computing (VNC) client and the video redirection server comprises a VNC server.
 13. The hardware memory of claim 11, wherein to provide the video stream to the framebuffer driver, the program instructions, upon execution, further cause the EC to maintain a Qt interface between the video redirection client and the framebuffer driver.
 14. The hardware memory of claim 13, wherein the program instructions, upon execution, further cause the EC to receive a keyboard or mouse event at the Qt interface, and transmit the keyboard or mouse event to the selected IHS.
 15. The hardware memory of claim 13, wherein the program instructions, upon execution, further cause the EC to enable a user to select the IHS among the plurality of IHSs using the Qt interface to establish a remote desktop session.
 16. The hardware memory of claim 11, wherein the framebuffer driver further comprises a Linux framebuffer (fbdev) configured to access the framebuffer memory.
 17. The hardware memory of claim 11, wherein the control signals further indicate at least one of: a pixel resolution, color depth, or a refresh rate.
 18. The hardware memory of claim 11, wherein the graphics core is configured to retrieve the frame data from the framebuffer memory in response to a command received via the AHB-to-PCI bridge.
 19. A method, comprising: receiving, via a video redirection client, a video stream produced by a video redirection server executed by a Baseboard Management Controller (BMC) of a selected IHS; providing the video stream to a framebuffer driver, wherein the frame buffer driver is configured to: (i) store frame data from the video stream onto a framebuffer memory; and (ii) in response to a determination that a host is not available, transmit control signals to a graphics core via an Advanced Microcontroller Bus Architecture (AMBA) high-performance bus (AHB)-to-Peripheral Component Interconnect (PCI) (AHB-to-PCI) bridge, wherein the graphics core is accessible via a PCI bus exclusively when the host is available; and transmitting the frame data to a display coupled to the chassis.
 20. The method of claim 19, wherein the framebuffer driver further comprises a Linux framebuffer (fbdev). 